1. Technical Field
The present disclosure relates to the field of biosensors and, in particular, to the immobilization of bio-recognition elements as, for example, cell receptors, enzymes, antibodies or nucleic acids, on sensor surfaces, in particular on flexible foils, by means of hydrogels.
2. Description of the Related Art
A biosensor is a device for the detection of an analyte. A biosensor comprises a bio-recognition element (sensitive biological element) and a detector element that transforms a signal resulting from the interaction of the analyte with the biological element into another signal that can be more easily measured and quantified. Immobilization of the bio-recognition element can be attained by passive adsorption, covalent binding via suitable linker chemistry and entrapment within hydrogel matrices or solid polymers and by inclusion in layers obtained by fusion of vesicles.
Hydrogels are especially attractive materials for fabricating electrochemical biosensing because a hydrated gel provides an excellent matrix encapsulation of functional enzymes, vaccine and cell sequestration and metabolite detection. In particular, the soft and hydrated environment of a swollen hydrogel can provide proteins with near-physiological conditions that minimize denaturation and help them to carry out their full biological functions. The three-dimensional geometry of hydrogels enables them to contain a much larger quantity of sensing reagent, thereby increasing their signal-to-noise ratio and sensitivity. Hydrogel photo-definable membranes have been introduced for providing immobilization of bio-recognition elements.